Display device

ABSTRACT

A display device for electronic computers, calculators and the like in which indicator electrode units, each comprising anode and cathode segments lying in the same plane in an envelope and in which all of the cathode segments are simultaneously energized for a predetermined desired configuration and the anode electrodes are energized on a time sequential basis in such a manner that only the cathode segments of the indicator electrode unit having its anodes energized will glow at a particular time. The individual respective cathode segments of each indicator unit are connected in parallel, and accordingly the number of leads to the display device is substantially reduced, as compared with conventional indicators which require separate leads for energizing the cathode segments respectively. The display device is provided with means for producing charged particles within the envelope to facilitate glow discharge of a particular indicator unit.

Frouws et al. 313/1095 United States Patent [1 1 [111 3,786,487Yanagisawa Jan. 15, 1974 DISPLAY DEVICE 3,652,891 3/1972 Janning3l3/l09.5

7 l 3,256,462 6/1966 Bauman 340/344 X l 5] Yanaglsawa, Kanagawa3,634,850 1/1972 Miyasaka 315/169 x Japan 7 [73] Assignee: SonyCorporation, Tokyo, Japan Primary EXamineT-DaVid TfaftoflAttorneyCarlton Hill et al. [22] Filed: Oct. 8, 1971 [21] Appl. No.:187,700 [57] ABSTRACT A display device for electronic computers,calculators [30] Foreign Application Priority Data and thelike in whichindicator electrode units, each 0 15 1970 J I 45 90650 comprising anodeand cathode segments lying in the apan same plane in an envelope and inwhich all of the cathode segments are simultaneously energized for a[52] Cl 340/336 313/1095 gag 5 predetermined desired configuration andthe anode 51] I t Gosh 5/36 electrodes are energized on. a timesequential basis in n Such a manner that only the cathode Segments ofthe [58] Field of Search 340/336, 343, 344, t l t d h d d 340/324 235/92SH 92 EA. 315/169 R 111 ica or e ec ro e um aving s ano es energize313/1095 will glow at a particular time. The individual respectivecathode segments of each indicator unit are connected in parallel, andaccordingly the number of [56] References cued leads to the displaydevice is substantially reduced, as UNITED STATES PATENTS compared withconventional indicators which require 3,675,065 7/1972 Warne 340/336 Xseparate leads for energizing the cathode segments re- 3679933 7/1972Nakada 81 313/109-5 X spectively. The display device is provided withmeans g z 32 for producing charged particles within the envelope to 11Cv c 3,609'658 9/1971 Sohan I I H 3 5/169 R X facilitate glow dischargeof a particular indicator unit. 3,4l8 509 12/1968 15 Claims, 13 DrawingFigures PATENTED 3, 786.487

SHEET U 0F 5 W .r 2,?? i i/15 2025 YUZU/Tl/ mm WA ATTORNEY PATENTEBJAH 151974 SHEET 5 OF 5 msgfia R; s E n 1N VENTOR WEI/Fl MNAHSAWA w) wwbATTORNEY DISPLAY DEVICE cRoss REFERENCE TO RELATED APPLICATIONS Thepresent invention is an improvement over the invention disclosed inpending applications, Ser. No. 128,888, filed Mar. 29, 1971; Ser. No.155,555, filed June 22, 1971; Ser. No. 172,855, filed Aug. 18,1971, Ser.No. 177,990 filed Sept. 7, 1971; and Ser. No. 180,727 filed Sept. 15,1971, all of which are assigned to the same assignee as the presentinvention.

BACKGROUND OF THE INVENTION 1. Field of the Invention:

This invention relates generally to a display device, and moreparticularly to a display device which is of particular utility whenemployed in electronic computers, calculators and so on.

2. Description of the Prior Art:

Generally, display devices, which are of the type including a pluralityof indicator units mounted inside a transparent envelope for displayingnumerals, symbols, letters or the like, have been used with electroniccounters and other various indicating devices. One example of suchdisplay device is the so-called Nixie tube in which an anode and aplurality of cathodes are aligned in a stack one above another and thecathodes are selectively energized to'provide a display of a desirednumeral or letter. Another type of indicator display tube utilizescathode segments mounted in a common plane and an anode in the form of awire screen or mesh mounted in a second plane.

For displaying a number containing a plurality of figures with the Nixietube, it is necessary to employ the same number of Nixie tubes as thatof the figures, which inevitably leads to bulkiness of an indicatordisplay device. Another display device is small and thin but requiresthe same number of leads as that involved in the case of the Nixie tubefor a number display. This introduces difficulty in the formation ofleads coming from the envelope and also complexity in external wir- U.S. Pat. No. 3,588,571, which is not prior art, discloses an indicatordisplay tube of the type in which many indicator electrode units, eachconsisting of an particles generated in the vicinity of the unit of themost significant unit do not momentarily flow in the region of the leastsignificant unit. Accordingly, in a display device of the type in whichthe indicator units are sequentially energized from the most significantunit to the least significant one on a time sequential basis to providea display, there is the possibility that glow of the indicator unit ofthe least significant unit incurs'a slight delay which results in itsglow brightness becoming lower. This phenomenon occurs not only in theabove display device but also in a display device in which every secondor fourth indicator unit is eneranode and a plurality of cathodesegments are formed 7 on an insulating plate with the cathode segmentsof each unit common to those in the other units and connected togetherby common leads, but the anodes are separately led out from theenvelope. This indicator display tube is advantageous in that the numberof the leads required is smaller than that of the Nixie tube.

The indicator units of such a display device are selectively energizedto glow on a time sequential basis as disclosed in the U. S. Pat. No.3,414,764. In a display device having, for example, twelve indicatorunits, the indicator units are sequentially supplied with apredetermined voltage in the order from the least significant unit tomore significant ones to provide a display. In this case, gas in thevicinity of the indicator unit energized is ionized and one part ofcharged particles flows in neighboring indicator units, by which, in theunit to be subsequently energized, there is produced an atmosphere inwhich the unit is ready to glow. In general, the indicator units of themost and least significant units are spaced apart from each other, sothat the charged gized. Also at the start of operation of the displaydevice, no charged particles exist, so that lighting of the indicatorunit of a first unit is likely to be delayed.

SUMMARY OF THE INVENTION The present invention is directed to a displaydevice of the type having a number of indicator electrode units withtheir anode and cathode segments formed in a common plane in which thereis providedmeans within an envelope to produce ionized ions therein. Insuch an arrangement, the cathode segments of each electrode unit commonto thoseof the other units are electrically interconnected andsimultaneously energized and the anodes are energized time-sequentiallyin such a manner that a particular electrode unit with its anodesenergized provides a display.

One object of this invention is to provide an improved display devicewhich is provided with many indicator electrode units and which hasmeans for insuring uniformity of brightness of' all units.

Another object of this invention is to provide a display device which isdriven on a time sequential basis and in which the indicator units arecaused to glow with uniform brightness.

Another object of this invention is to provide a display device which isdriven on a time sequential basis and is arranged to eliminatesubstantially any delay in lighting indicator units.

Still another object of this invention is to provide a display devicewhich uses a power source pilot device of a computer, a calculator orthe like as a means for preventing a delay in lighting a particularindicator unit. I Other objects, features and advantages of thisinvention will become apparent from the following description taken inconjunction with the accompanying drawmgs.

BRIEF DESCRIPTION, OF THE DRAWINGS FIG. I is a plan view schematicallyillustrating one example of a display device of this invention;

FIG. 2 is a plan view of a cover plate of the display device of thisinvention;

FIG. 3 is a plan view of the glass backing plate of the invention;

FIG. 4 is a sectional view taken on line IV-IV of FIG. 2;

FIG. 5 is a sectional view taken on line V-V of FIG.

FIG. 6 is a plan view of the backing plate illustrated in FIG. 3. with aplurality of interconnecting leads formed thereon;

FIG. 7 is a plan view of the backing plate of FIG. 6 with an insulatinglayer formed over the interconnecting leads;

FIG. 8 is a plan view of the backing plate of FIG. 7 with a plurality ofindicating units and selecting leads formed over the insulating layer;

FIG. 9 is a plan view of the backing plate of FIG. 8 with an insulatinglayer formed thereon;

FIG. 10 is a sectional view taken on line X-X of FIG. 1;

FIG. 11 is a circuit diagram showing a schematic indicator assemblytogether with a drive circuit therefor;

FIG. 12 is a graph, for explaining this invention; and

FIG. 13 is a sectional view schematically showing another example ofthis invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS In FIG. 1 there is illustratedgenerally one example of a gaseous glow type display device 1 producedaccording to this invention. The display device 1 is made up of a baseplate 2 of an insulating material such as, for example, glass. Aplurality of indicator units 40, 41, 42, 43, 44 and 45 of the samepattern are formed by printing techniques on the base plate 2 inalignment with one another and a transparent cover plate 3, as of glass,is attached at its periphery in an air-tight manner to the base plate 2and its center is spaced a predetermined distance from the indicatorunits.

The display device 1 is constructed in the following manner: Theinsulating base plate 2 such as illustrated in FIG. 3 has the indicatorunits and the interconnecting leads formed thereon. The transparentcover plate 3 is attached to the base plate 2 after the indicator unitsare formed. The cover plate 3 is formed with a depression or hollowportion 4 in which the indicator units are received as shown in FIG. 4.

Both of the plates 2 and 3 may be made of glass and generally the baseplate 2 is larger in area than the cover plate 3 as may be observed bycomparing FIGS. 2 and 3.

FIG. 4 is a sectional view taken on line IV-IV of FIG. 2 and illustratesthe depression 4 in the cover plate 3.

FIG. is a sectional view taken on line V-\/ of FIG.

FIG. 6 is an enlarged plan view of the base plate 2 and illustrates aplurality of interconnecting leads to 18 which are formed on theinsulating base plate 2 by suitable thin film techniques such as, forexample, by printing. It is to be particularly noted that theinterconnecting leads 10 to 18 are grouped so that they will align withindicator units to be formed above a particular group. Thus, theinterconnecting leads for the first indicator unit are designated bynumerals 10 to 18 and the interconnected leads for the second unit aredesignated by numerals 10' to 18'. The interconnecting leads are formedof silver paste which adheres well to the glass base plate 2. h

After the interconnecting leads are formed by printed circuit techniqueson the base plate 2, theplate and leads are baked to provide suitablebonding.

It is to be realized that the lengths of the interconnecting leads 10 to18 are such that they will be capable of interconnecting the cathode andanode elements of the indicator units to suitable selecting leads aswill become more apparent in the description.

FIG. 7 is a plan view of the base plate 2 in which a glass insulatinglayer 20 has been deposited on the base plate 2 so as to cover asubstantial portion of the interconnecting leads 10 to 18. Theinsulating layer 20 may be formed by a glass coating method by sprayingtwo or three times and then by drying it to provide it with a suitableinsulation coating 20 over the interconnecting leads.

Windows are formed in the insulating layer 20 at opposite ends at eachof the interconnecting leads 10 to 18 so as to allow electricalconducting paths to be formed through the insulating layer 20 to theinterconnecting leads 10 to 18. For example, windows 30a and 30b areformed through the insulating layer 20 at opposite ends of theinterconnecting lead 10. Windows 31a and 31b are formed at opposite endsof the interconnecting lead 11 and additional windows 32a and 32bthrough 38a and 38b are respectively formed at opposite ends of leads 12to 18. Additional windows intermediate the ends of lead 14 are formedand are designated 34c and 34d.

It is to be realized, of course, that the windows formed through thelayer 20 are formed for each of the indicator units although they areonly particularly numbered in FIG. 7 for the first indicator unit.

FIG. 8 illustrates the next step of the method of mak- I ing theindicator unit and illustrates a plurality of indicating units 40 to 45which are formed on the top of the insulating layer 20.

In the next step the plurality of indicator units 40 to 45 (the numberdepending upon the desired number) are formed on the insulating layer 20and aligned with the windows through the layer 20 so that electricalcontact will be made with the interconnecting leads. Each of theindicator units comprises electrically conducting anode segments 51, 52and 53 as well as an associated plurality of cathode elements 61 to 68.At the same time, a plurality of selecting leads 71 to 78 are formed onthe insulating layer 20 with the leads 71 to 74 extending along the topof the indicator units 40 to 45 as shown in FIG. 8 and the selectingleads 75 to 78 extending along the bottom of the indicator units 40 to45 as shown in FIG. 8. The anode and cathode segments and selectingleads are formed by suitable thin film techniques and are formed so asto align with the windows 30a to 38a and 30b to 38b so that electricalconnections will be made between the selecting leads 71 to 78 and theanode and cathode segments.

A plurality of external leads 81 to 84 are formed on the insulatingplate 2 adjacent the lower edge relative to FIG. 8 and are respectivelyconnected to the selecting leads 71 to 74. A plurality of external leads91 to 94 are respectively connected to the selecting leads 75 to 78 andare formed on the insulating plate 2 along the bottom edge as shown inFIG. 8.

It is to be realized that the indicator units 40 to 45, the selectingleads 71 to 78 and the external leads 81 to 84 and 91 to 94 are formedat the same time by a silk screen process and when the indicator units40 to 45 and selecting leads 71 to 78 are printed on the insulatinglayer 20, each of the cathode elements 71 to 68 and anode elements 51 to53 are respectively connected to the associated selecting leads throughthe windows 30a to 38d formed in the insulating layer 20. For example,the cathode element 62 is formed so that it aligns with window 31b whichconnects it to one end of the interconecting lead 11 and the selectinglead 74 is formed over the window 310 so'that the selecting lead 74 isconnected to the cathode segment 62 through the interconnecting lead 11.Simultaneously, all of the corresponding cathode segments 62 of allofthe indicator units '40 to 45 are connected to lead 74 throughassociated windows and thus all of the segments 62 of all of theindicator units are electrically connected together and to the externallead 84. Similarly, all of the cathode segments 61 are connected byinterconnecting lead to selecting lead 72 and to external lead 82. Allof the cathode segments 63 are connected by interconnecting leads 13 toselecting lead 73 which is connected to external lead 83. Each of thecathode segments 64 is connected by interconnecting lead 12 to selectinglead 71 which is connected to external lead 81. Each of the cathodesegments 65 is connected by interconnecting lead to selecting lead 75and to external lead 91. Each of the cathode segments 66 is connected byinterconnecting lead 16 to selecting lead 76 which is connected toexternal lead 92. Each of the cathode segments 67 is connected byinterconnecting lead 17 to selecting lead 77 which is connected toexternal lead 93. Each of the cathode segments 68 is connected byinterconnecting lead 18 to selecting lead 78 which is connected to theexternal lead 94.

Thus, in the structure defined thus far, the associated cathode segmentsof all of the indicator units 40 to 45 are electrically connectedtogether and thus can be electrically energized by the eight cathodeselecting leads 81 to 84 and 91 to 94. The three anode segments 51, 52and 53 of each of the indicator units 40 to 45 are interconnectedtogether by the interconnecting lead 14 and a separate external lead isformed along the lower edge of the insulating plate 250 that the anodesegments of each of the indicator units can be individually energized.For example, an external lead 110 is connected to interconnecting lead14 of the indicator unit 40 which is connected to the anode segments 51,52 and 53 of the indicator unit 40 but not to the anode leads of anyother indicator unit and the indicator unit 40 alone will be energizedwhen the external lead 110 is energized with a selective pattern of thecathode segments. I

Likewise, the anode segments of the indicator unit 41 are connectedthrough an interconnecting lead to the external anode lead 111 for theindicator unit 41. An external lead 112 is connected to the associatedanode segments of the, indicator unit 42 in a similar manner. Anexternal lead 113 is connected to the anode segments of the indicatorunit 43 and an external lead 114 is connected to the anode segments ofthe indicator unit 44. An external lead 115 is connected to the anodesegments of the indicator unit 45.

The display device is adapted to prevent an incorrect message displaywhich is caused by accidental discharge of the indicator units. For thispurpose, in the illustrated example an auxiliary electrode or barrierelectrode designated at 100 is utilized. The barrier electrode 100 maybe formed around the indictor units 40 to 45 on the insulating layer atthe same time as the indicator units and leads and has suitable windowsfor the indicator units as shown. A lead 101 is also formed on theinsulating layer 20 and extends from the barrier electrode 100 to anexternal lead 102 so that a suitable voltage may be applied. The leads101 and 102 are formed at the same time that the barrier electrode 100is formed. The leads, cathode and anode segments and barrier electrodeare all formed of silver paste which adheres well to the glassinsulating layer 20.

Further, in this step a keep-alive means 105 for producing chargedparticles is provided adjacent the indicator unit 45 of the leastsignificant unit. The keepalive means 105 comprises cathode and anodeelec- 5 trodes which are formed on the insulating layer 20. A

pair of leads 108 and 109 are also formed on the insulating layer 20 toextend from the electrodes 106 and 107 to a pair of external leads 128and 129, respectively, so that a suitable voltage may be appliedtherebetween.

in the next step, as shown in FIG. 9, a second insulating layer' 20 ofglass is deposited over the selecting leads 71'to 78 and 101 but theindicator units and the keep-alive means 105 are left uncovered by thissecond insulating layer 120. in other words, the cathode segments 61 to68 and the anode segments 51 to 53 of each of the indicator units and atleast the cathode and anode electrodes 106 and 107 of the keep-alivemeans 105 are left uncovered by the second insulating layer 120. Theexternal leads are also left uncovered by the second insulatinglayer120.

Since the cathode segments of each indicator unit are bombarded byionized ions emitted from the space discharge layer which can cause themto sputter, it is necessary to form the cathode segments of a metalwhich resists sputtering and which has a low work function.

For accomplishing this, a thin nickel layer is formed on the variouselements of the plurality of indicator units 40 to 45, over the barrierelectrode 100 and over the electrodes 106 and 107 by electroplating in asuitable plating bath.

After the indicator units areformed on the base plate 2, the cover plate3 is attached to the base plate 2 as shown in FIG. 10 by suitable cementor other means so as to foml a sealed chamber between the base plate 2and cover plate 3 which encloses the indicator units. The external leadshave portions which extend beyond the cover plate 3 on the base plate 2so that electrical connection can be made.

The base plate 2 is formed with an opening to which an exhaust tube (notshown) may be connected so as to evacuate the space between the coverplate 3 and the base plate 2 and a suitable ionizing gas may be inserted into the space between the cover plate 3 and the base plate 2.

FIG. 11 is a schematic circuit diagram showing a drive circuit for thedisplay device according to this invention. 1n the figure the anodeelectrodes of each indicator unit of the display device 1 are designatedby 51. The anode electrodes 51 are respectively connected to a firstsignal input source 130 through first switching means, for example,transistors 120 to 125. While, the corresponding cathode segments 61 ofthe indicator units are connected through a lead 72 to a secondswitching means, for example, a transistor 141 and, similarly, thecorresponding cathode segments 62 to 68 of the indicator units areconnected to transistors 142 to 148 through leads respectively. Thesecond switching means are connected to, for example, a calculatorcircuit 151 through a second input signal source 150. Further, a firstDC power source 152 is provided for applying a predetermined DCpotential to the anodes 51 and the cathode segments of the respectiveindicator units and the barrier electrode 100 through a resistor.Further, a second DC power source 153 is provided for impressing apredetermined DC voltage between the anode and cathode electrodes 107and 106 of the keep-alive means 105. The voltage to the keepalive means105 may be supplied from the first power source 152 without providingthe second power source 153.

The first input signal source 130 serves to determine which indicatorunit becomes energized. The source 130 may take the form of a counter sothat its output terminals 130a to 130f are energized in a predeterminedsequence.

The first and second input signal sources 130 and 150 are synchronouslyenergized in such a manner that when their associated first and secondswitching means are individually closed at predetermined intervals,particular indicator units are activated to indicate particular numbersin a particular sequence. This sequence of numbers corresponds to therelationship between the outputs of the first and second signal sources130 and 150. As shown, there may be provided a synchronizing clock pulsesource 154 to supply synchronizing signals to the first and second inputsignal sources 130 and 150.

With the above described arrangement, since the first and second signalsources 130 and 150 sequentially drive the switching means 121 to 125and 141 to 148 in synchronism as by means of clock pulses, a particularindicator unit is ignited which is simultaneously energized by both thefirst and second input signal sources. That is, the cathode segments ofeach indicator unit can sequentially be caused to glow in a timedivisional manner.

With such a display device, the indicator units are sequentiallyenergized to glow'on a time sequential basis in an order of, forexample, 45, 44, 40, thereby to display a number containing a'pluralityof figures. In such a case, when the first indicator unit 45 isenergized again after the indicator unit 40 has been driven, chargedparticles produced by previous discharge of the first indicator unit 45have already become extinct in its vicinity and charged particlesproduced by discharge of the indicator unit do not flow to the indicatorunit because the both indicator units are not close to each other, sothat initiation of glow of the indicator 45 is delayed, which lowers itsglow intensity as compared with that of the other indicator units 44 to40. This is illustrated in FIG. 12. Namely, in the event thatpredetermined positive voltages E E E E E43, are sequentially applied tothe indicator units in an order of 41, 40, 45, 44, 43, the indicatorunit 45 starts to discharge at a time delayed by 1- behind that whensupplied with the voltage E Accordingly, the glow intensity of theindicator units except that 45 varies with time as indicated by curvesL41, L respectively, but the glow intensity of the indicator unit 45varies as indicated by a curve L so that the maximum value of glowintensity is smaller and the time for glow discharge is shorter, ascompared with those of the other indicator units. As a result of this,the glow intensity of the indicator unit 45 becomes lower which makes itimpossible to provide a display of uniform intensity. Especially in thecase where the glass envelope is extremely flat as depiected in FIG. 10,the atomsphere in the envelope is not fluid, so that while an erroneousdisplay may well be avoided, the phenomenon such as above described islikely to occur.

With the present invention, however, the keep-alive means 105 consistingof the anode and cathode electrodes 107 and 106 is disposed adjacent theindicator unit 45 as previously described. The keep-alive means isdriven by the DC power source 153 as will hereinbelow be described indetail. That is, the DC power source 153 includes switching means (notshown), which is controlled by a pulse from the clock pulse source 154in such a manner as to be closed immediately before or after terminationof glow discharge of the indicator unit 40. When the DC power source 153is driven under the control of the clock pulse source 154, apredetermined voltage indicated by E in FIG. 12 is applied between theanode and cathode electrodes 107 and 106 of the keep-alive means 105 tocause glow discharge therebetween, so that gas in the vicinity of themeans 105 is ionized, namely particles are charged positive or negative.

With such an arrangement as above described, the keep-alive means 105 isdriven immediately before the indicator unit 45 is energized, so thatthe indicator unit 45 is made ready for glow discharge by the residualionization of the keep-alive means 105, that is, charged particlesproduced by the means 105. This ensures that the indicator unit 45 alsoinitiates discharge immediately when supplied with the predeterminedvoltage, as is the case with the other indicator units 44 to 40.Accordingly, the maximum value of glow intensity of the indicator unit45 and the time for the glow discharge thereof are equal to those of theother indicator units 44 to 40 as indicated by a curve L in FIG. 12,thus providing a display with uniform glow intensity as a whole. V

In the case where the indicator units are driven in an order of 45, 43,41, D,, ,-and then in an order of 44, 42, D,,, a keep-alive means may beprovided adjacent the indicator unit 44, for example, between theindicator units 44 and 45, in which case the keepalive means is drivenafter driving of the indicator unit D,, and then the indicator unit 44is driven. Further, when the indicator units 45, 44 and 43 aresequentially driven and then the indicator unit D, is driven withoutdriving the preceding ones 42 to D,, a similar keepalive means isprovided adjacent the indicator unit D,,, in which case the keep-alivemeans is driven first and then the indicator unit D, is driven. In thecase where glow of the keep-alive means 105 is a'nuisance or cannotreadily be distinguished from that of the indicator units 40 to 45, ablack film or the like may be coated on the surface of the cover 3 at anarea overlying the keep-alive means 105. Further, the keep-alive means105 may be driven at all times or in association with closing of a powersource switch so as to avoid a time lag in initial ignition of theindicator units. It is also possible to coat the cathode and anodeelectrodes of the keep-alive means with a radioactive material.

In FIG. 13 there is illustrated another example of this invention. Inthis figure elements corresponding to those in FIGS. 1 and 2 areidentified by the same reference numerals and no detailed descriptionthereon will be repeated. In the present example, the indicator unitsare sequentially energized in repeating cyclic order of 45, 44, D,,, inwhich case a charged particle producing means, for example, aluminescent element 200 is provided in the proximity of the firstindicator unit 45, for example, immediately on the right thereof. Theluminescent element 200 may be, for example, a luminescent diode, anincandescent bulb, a neon tube or the like. In the illustrated example,a light transparent portion (a transparent member or an aperture) 201 isprovided in the glass plate 2 near the indicator unit 45 and aluminescent diode 200 serving as the luminescent member is disposed onthe plate below the light transparent portion 201. Reference numeral 202designates a case for holding the luminescent element 200 in position onthe plate 2.

The luminescent member 200 is associated with the power source for thedisplay device. in practice, when the display device is incorporated inan electronic instrument such as an electronic desk computer, theluminescent member is associated with the power source of the electronicinstrument. In the present example, an AC voltage from an AC powersource AC is converted by a power source 203 into a desired DC voltageand then supplied to the display device and other. parts of theelectronic instrument but, at the same time, the DC voltage from thepower source circuit 203 is directly applied to the luminescent diode200 acting as the luminescent element. Reference character SW indicatesa power source switch, through which the AC power source AC is connectedto the power source circuit 203. Where the luminescent element 200 is,for example, an incandescent bulb, a neon lamp or the like, it is alsopossible to connect it between the power source switch SW and the powersource circuit 203 and supply the AC voltage thereto.

Turning on the power source switch SW, the DC voltage is applied fromthe power source circuit 203 to the luminescent diode 200 as well as thedisplay device and the other parts of the electronic instrument to lightthe diode 200. Thus, photoelectrons, that is, charged particles arealways produced by stimulation with light emitted from theluminescentdiode 200 in the vicinity of the indicator unit 45. Further, by lightingof the luminescent diode 200, it is known visually that the power sourceof the display device or that of the electronic instrument provided withthe display device has been turned on.

In the case where the indicator units are sequentially driven in anorder from 45 to D as previously described in connection withtheforegoing example, the indicator unit 45 immediately initiates dischargewhen a voltage is applied between its anode and desired cathode segmentsbecause charged particles are always produced in the neighborhood of theindicator unit 45. Accordingly, the maximum value of glow intensity ofthe indicator unit 45 and the time for glow discharge thereof are equalto those of the other indicator units, thus ensuring to produce adisplay with uniform glow intensity as a whole.

Such a luminescent element also serves as a pilot lamp of the powersource, so that a special indicator therefor need not be provided andthe luminescent element does not disturb the display produced by thedisplay device.

The production efficiency of the charged particles becomes higher as thewavelength of light from the luminescent element 200 becomes shorter.

It is preferred for the function of the power source pilot lamp that thelightof the luminescent element is selected to be different in colorfrom that of the indicator units or that the luminous portion of theluminescent element is formed in a peculiar configuration.

Of course, the luminescent element 200 may be disposed on the inside ofthe envelope formed with the plate 2 and the glass cover 3.

The power source associated with the luminescent element 200 may be abattery or the like.

Further, the relative arrangement of the cathode and anode segmentsmaking up each indicator unit is not limited specifically to the abovedescribed one but may be selected at will.

Needless to say, the present invention is also applica ble to a displaydevice in which indicator units for displaying letters, symbols or thelike are sequentially arranged.

The display device of this invention may be used with not only theelectronic desk computer but also a telephone, a measuring instrument, avending machine and so on.

It will be apparent that many modifications and variations maybeeffected without departing from the scope of the novel concepts ofthis invention.

1 claim as my invention:

1. A display device comprising: an indicator tube having a base plate ofinsulating material; v

a plurality of indicator units aligned on one side of said plate, eachof said indicator units comprising a plurality of cathode segmentsarranged in a predetermined configuration on said base plate and atleastone anode electrode forming a part of each indicator unit disposedon said base plate;

a transparent cover sealed to said base plate and spaced above saidcathode segments and said anode electrodes thereby forming a closedchamber with said cathode segments and anode elec trodes therein;

an ionizable gas in said chamber;

means for applying a bias potential to each of said indicator unitsbetween the anodes and selected ones of said cathode segments thereof ona time sequential basis beginning with a first one of said indicatorunits and continuing through a last one of said indicator units; and

means for locally ionizing said gas adjacent said first indicator unit,

means for energizing said last means immediately prior to the time whensaid first indicator unit is energized, whereby the time for causingsaid first indicator unit to glow is substantially the same as for saidremaining indicator units.

2. A display device according to claim 1, wherein said means for locallyionizing said gas includes a cathode electrode and an anode electrode.

3. A display device according to claim 1, wherein said means for locallyionizing said gas includes a luminescent element disposed in proximityto said first indicator unit on said base plate.

4. A device according to claim 1 in which each of said cathode segmentsand each of said anode segments have a thin nickel coating thereon.

5. An indicator unit comprising:

a base plate of insulating material;

a plurality of indicator units on one side of the base plate;

a transparent cover sealed to said base plate and forming a chambertherewith enclosing said indicator units;

an ionizable gas within said chamber;

each of said indicator units including a plurality of cathode segmentsin a discrete pattern located in a single plane; and at least one anodesegment for each of said indicator units in the plane of said cathodesegments;

an electrode for each indicator unit having portions which surrounds thecathode segments of that indicator unit and located in the same plane assaid cathode segments;

the cathode segments of each indicator unit being connected throughleads to similarly positioned cathode segments of 'all indicator units;

means during each indicating cycle for time sequentially applying a biaspotential to each of said anode segments sufficient to cause ionizationof gas adjacent those cathode segments of each indicator unit whoseanode segment is so biased when such cathode segments are given adecoding potential negative with respect to said anode segment;

means for sequentially connecting a decoding potential to those cathodesegments of each indicator tube to form the desired pattern;

means for applying a biasing potential to said electrode with apotential insufficient to cause ionization but sufficient to act as anion barrier;

keep-alive electrode means adjacent said indicator unit which is firstto be energized during each indicating cycle; and

means for energizing said keep-alive electrode means each cycle justprior to the energization of the first of said indicator units in saidcycle.

6. A device according to claim in which each of said indicator units andeach of said barrier electrodes have an electro-plated coating of nickelthereon.

7. A display device comprising;

A plurality of indicator units formed on a plate of an insulatingmaterial for sequential energization, each of said plurality ofindicator units consisting of a plurality of first electrode segmentslying in a single plane arranged in a predetermined configuration and atleast one second electrode in proximity to each indicator unit group ofsaid first electrode segments also lying in said single plane;

a plurality of first leads each connected to corresponding ones of saidfirst electrode segments of said indicator units;

a plurality of second leads each connected to a different one of saidsecond electrodes of said indicator units;

a transparent cover of an insulating material covering at least one sideof said insulating plate to form an envelope;

an ionizable gas sealed in said envelope; and

means for producing ionized charged particles within said envelopeadjacent at least one of said indicator units prior to activation ofsaid one indicating unit.

8. A display device as claimed in claim 7, wherein said indicator unitslie on said insulating plate in alignment with one another and saidtransparent cover is mounted on said plate so as to accommodate all ofthe said indicator units and ionized charged particle producing means.

9. A display device as claimed in claim 8, wherein said charged particleproducing means comprises an anode electrode and a cathode electrode tobe supplied with a predetermined voltage therebetween.

10. A display device as claimed in claim 9 wherein said cathode andanode electrodes of said charged particle producing means are formed onsaid insulating plate.

11. A display device as claimed in claim 8, wherein said particleproducing means lies in alignment with said indicator units.

12. A display device as claimed in claim 7, wherein said particleproducing means is an electric-to-light conversion element.

13. A display device as claimed in claim 12, wherein saidelectric-to-light conversion element is disposed on said insulatingplate.

14. A display device as claimed in claim 12, wherein saidelectric-to-light conversion element is energized by turning on a powersource switch.

15. A display device comprising an indicator tube having:

a base plate of insulating material;

a plurality of indicator units aligned on one side of said plate, eachof said indicator units comprising a plurality of cathode segmentsarranged in a pre determined configuration on said base plate and atleast one anode electrode forming a part of each indicator unit disposedon said base plate;

a transparent cover sealed to said base plate and spaced above saidcathode segments and said anode electrodes thereby forming a closedchamber with said cathode segments and anode electrodes therein;

an ionizable gas in said chamber;

means for applying a bias potential to each of said indicator unitsbetween the anodes and selected ones of said cathode segments thereof ona time sequential basis beginning with a first one of said indicatorunits and continuing through a last one of said indicator units; and

means for locally ionizing said gas adjacent said first indicator unit,

means for energizing said last means immediately prior to the time whensaid first indicator unit is energized, whereby the time for causingsaid first indicator unit to glow is substantially the same as for saidremaining indicator units,

said base plate having a transparent portion therethrough adjacent saidvfirst indicator unit, and wherein said means for locally ionizing saidgas includes a light producing source below said transparent portion forionizing the gas adjacent said first indicator unit just prior toenergization of said first indicator unit.

1. A display device comprising: an indicator tube having a base plate ofinsulating material; a plurality of indicator units aligned on one sideof said plate, each of said indicator units comprising a plurality ofcathode segments arranged in a predetermined configuration on said baseplate and at least one anode electrode forming a part of each indicatorunit disposed on said base plate; a transparent cover sealed to saidbase plate and spaced above said cathode segments and said anodeelectrodes thereby forming a closed chamber with said cathode segmentsand anode electrodes therein; an ionizable gas in said chamber; meansfor applying a bias potential to each of said indicator units betweenthe anodes and selected ones of said cathode segments thereof on a timesequential basis beginning with a first one of said indicator units andcontinuing through a last one of said indicator units; and means forlocally ionizing said gas adjacent said first indicator unit, means forenergizing said last means immediately prior to the time when said firstindicator unit is energized, whereby the time for causing said firstindicator unit to glow is substantially the same as for said remainingindicator units.
 2. A display device according to claim 1, wherein saidmeans for locally ionizing said gas includes a cathode electrode and ananode electrode.
 3. A display device according to claim 1, wherein saidmeans for locally ionizing said gas includes a luminescent elementdisposed in proximity to said first indicator unit on said base plate.4. A device according to claim 1 in which each of said cathode segmentsand each of said anode segments have a thin nickel coating thereon. 5.An indicator unit comprising: a base plate of insulating material; aplurality of indicator units on one side of the base plate; atransparent cover sealed to said base plate and forming a chambertherewith enclosing said indicator units; an ionizable gas within saidchamber; each of said indicator units including a plurality of cathodesegments in a discrete pattern located in a single plane; and at leastone anode segment for each of said indicator units in the plane of saidcathode segments; an electrode for each indicator unit having portionswhich surrounds the cathode segments of that indicator unit and locatedin the same plane as said cathode segments; the cathode segments of eachindicator unit being connected through leads to similarly positionedcathode segments of all indicator units; means during each indicatingcycle for Time sequentially applying a bias potential to each of saidanode segments sufficient to cause ionization of gas adjacent thosecathode segments of each indicator unit whose anode segment is so biasedwhen such cathode segments are given a decoding potential negative withrespect to said anode segment potential; means for sequentiallyconnecting a decoding potential to those cathode segments of eachindicator tube to form the desired pattern; means for applying a biasingpotential to said electrode with a potential insufficient to causeionization but sufficient to act as an ion barrier; keep-alive electrodemeans adjacent said indicator unit which is first to be energized duringeach indicating cycle; and means for energizing said keep-aliveelectrode means each cycle just prior to the energization of the firstof said indicator units in said cycle.
 6. A device according to claim 5in which each of said indicator units and each of said barrierelectrodes have an electro-plated coating of nickel thereon.
 7. Adisplay device comprising: A plurality of indicator units formed on aplate of an insulating material for sequential energization, each ofsaid plurality of indicator units consisting of a plurality of firstelectrode segments lying in a single plane arranged in a predeterminedconfiguration and at least one second electrode in proximity to eachindicator unit group of said first electrode segments also lying in saidsingle plane; a plurality of first leads each connected to correspondingones of said first electrode segments of said indicator units; aplurality of second leads each connected to a different one of saidsecond electrodes of said indicator units; a transparent cover of aninsulating material covering at least one side of said insulating plateto form an envelope; an ionizable gas sealed in said envelope; and meansfor producing ionized charged particles within said envelope adjacent atleast one of said indicator units prior to activation of said oneindicating unit.
 8. A display device as claimed in claim 7, wherein saidindicator units lie on said insulating plate in alignment with oneanother and said transparent cover is mounted on said plate so as toaccommodate all of the said indicator units and ionized charged particleproducing means.
 9. A display device as claimed in claim 8, wherein saidcharged particle producing means comprises an anode electrode and acathode electrode to be supplied with a predetermined voltagetherebetween.
 10. A display device as claimed in claim 9, wherein saidcathode and anode electrodes of said charged particle producing meansare formed on said insulating plate.
 11. A display device as claimed inclaim 8, wherein said particle producing means lies in alignment withsaid indicator units.
 12. A display device as claimed in claim 7,wherein said particle producing means is an electric-to-light conversionelement.
 13. A display device as claimed in claim 12, wherein saidelectric-to-light conversion element is disposed on said insulatingplate.
 14. A display device as claimed in claim 12, wherein saidelectric-to-light conversion element is energized by turning on a powersource switch.
 15. A display device comprising an indicator tube having:a base plate of insulating material; a plurality of indicator unitsaligned on one side of said plate, each of said indicator unitscomprising a plurality of cathode segments arranged in a predeterminedconfiguration on said base plate and at least one anode electrodeforming a part of each indicator unit disposed on said base plate; atransparent cover sealed to said base plate and spaced above saidcathode segments and said anode electrodes thereby forming a closedchamber with said cathode segments and anode electrodes therein; anionizable gas in said chamber; means for applying a bias potential toeach of said indicator units between the anodes and selected ones ofsaid catHode segments thereof on a time sequential basis beginning witha first one of said indicator units and continuing through a last one ofsaid indicator units; and means for locally ionizing said gas adjacentsaid first indicator unit, means for energizing said last meansimmediately prior to the time when said first indicator unit isenergized, whereby the time for causing said first indicator unit toglow is substantially the same as for said remaining indicator units,said base plate having a transparent portion therethrough adjacent saidfirst indicator unit, and wherein said means for locally ionizing saidgas includes a light producing source below said transparent portion forionizing the gas adjacent said first indicator unit just prior toenergization of said first indicator unit.